Added checks to sdist command.
Added checks to sdist command.

Make sure that the generated .c files are in sync with .pyx files.

ThomasA/pywt,aaren/pywt,nigma/pywt,PyWavelets/pywt,rgommers/pywt,grlee77/pywt,grlee77/pywt,ThomasA/pywt,ThomasA/pywt,eriol/pywt,eriol/pywt,michelp/pywt,kwohlfahrt/pywt,rgommers/pywt,Dapid/pywt,Dapid/pywt,Dapid/pywt,kwohlfahrt/pywt,rgommers/pywt,nigma/pywt,aaren/pywt,rgommers/pywt,eriol/pywt,michelp/pywt,aaren/pywt,kwohlfahrt/pywt,nigma/pywt,PyWavelets/pywt,michelp/pywt